This invention is involved in the field of material handling vehicles, particularly backhoes.
A backhoe is commonly used in the art to dig ditches, foundations, or basements and, as such, requires in many instances that the bottom level of the ditch, foundation or basement be maintained at a given level or desired elevation or slope. The accomplishment of this depth in the normal operation of a backhoe is by sight, i.e. the operator judging from the relative distance from his position to the location of the bucket as it is placed in the ditch. Although the problem is difficult even on level terrain, the maintenance of a constant depth becomes more complex on irregular terrain. Although highly experienced operators may be able to attain depth accuracies that are sufficient, the problem is compounded by inexperienced operators, who are unable to maintain a constant depth required for particular situations. In addition, where it is desired to have a particular ditch drop or rise in elevation, the judgement of this by the operator is very difficult despite the amount of experience.